Amino acids and peptides are well known in the pharmaceutical, natural medicine and veterinary medical industries as constituents of products such as intravenous foods and as special foods for relieving certain trauma. To date, it is chiefly extracts from blood plasma and protein hydrolysate produced using pancreatic enzymes from pigs and calves that have been used in this area. The invention provides the pharmaceutical industry with the possibility of obtaining a supply of amino acids and peptides of a hitherto unknown quality.
Amino acids and ultrashort peptides are also used for biotechnological processes, for example, when a highly potent culture medium is to be produced. A limitation for all industry that cultivates single cell organisms or cell substrates from higher organisms is the supply of culture media of adequate quality. Defects or a high price are limiting factors. Moreover, amino acids or peptides produced by biotechnological methods generally contain growth-inhibiting substances which can be avoided by using the products produced by the method of the invention. The combination of spectra of natural amino acids and biological micronutrients/minerals produced by the process described yields a unique product for the preparation of culture media for the biotechnological industry. Moreover, the technique can recycle proteins from many types of cultures back to amino acids and peptides which can then be reused.
Peptides/amino acids are used in the food processing industry as binders, emulsifiers, flavouring additives and the like. The uses are considerable and are increasing. The most used peptides and amino acids in the food processing industry derive from soya beans and milk. Amino acids and peptides from soya and milk in particular are known for causing allergenic reactions which can only be avoided by using another peptide/amino acid composition which does not derive from these sources, or a peptide/amino acid composition from soya or milk that has been sufficiently modified so as not to cause these reactions. Therefore, there is a great need for a method which provides a composition of amino acids and peptides that can also derive from soya and/or milk, but which do not cause allergenic reactions. Products from most animal sources have not attained the same degree of utilisation as there are no extraction techniques that maintain the functionality of the product whilst removing undesired quality-reducing components such as salt and fat.
Many different compositions of proteins, peptides and amino acids deriving from different sources are used in the production of animal feed. The composition of the peptides, the amino acids and the proteins is also very important in the production of feed as the animals' growth potential is dependent upon a balanced feed intake. Therefore, in this area too, there is a great need for a method which produces any desired composition that provides optimal growth conditions for the animals.
In the following the term “endogenous” enzymes is used as a term for the enzymes originating within the protein product as opposed to the “exogenous” enzymes which are extraneous enzymes added to the raw protein material during traditional hydrolysis. One example of an “exogenous” enzyme is “Deterzyme APY”, which is a bacterial protease (E.C. 3.4.21) prepared by controlled fermentation of Bacillus alcalophilus, and which can be purchased from a number of suppliers. The term “endogenous” enzymes is also used to mean enzymes extracted from other similar natural enzyme materials or raw materials, preferably from cold-blooded animals.
The term “hydrolysate” is used in the text below as a designation for the raw materials that are being processed, i.e., that the warmed and pH-adjusted mixture of raw material and water constitutes the hydrolysate. This applies in particular to aspects a) and b) of the invention.
There are a number of patents in the field of the invention, as for example RU 2103360 which describes a nutrient medium for culturing eucaryotic cells and a method for preparing a hydrolysate from fish internals which is prepared by proteolytic hydrolysis. This hydrolysis process is carried out at a high pH adjusted with sodium hydroxide, by using temperature inactivation, filtering and drying in which the fish offal is mixed with distilled water in a ratio of 1:1. The hydrolysis is carried out at a temperature of +40°-+42° C. until a weight percentage of amino nitrogen of 5.5-6-5% and a weight percentage of free amino acids of 50-60% are obtained.
SU 1755417 also discloses a method for the production of hydrolysates from raw fish material in a fermenter to which a fermentation preparation is added, followed by a filtering and drying of the hydrolysate produced, wherein non-crushed raw material is used that is fed periodically into the fermenter.
RU 1559466 describes a method for the production of hydrolysates, which requires the crushing of fish products or scrap from the processing thereof, mixing with water, heating the mixture, adding a proteolytic fermentation preparation, fermenting, filtering and drying, wherein raw materials and water are mixed in a ratio of 2:1-1:1, and heated to a temperature of +40°-+45° C., whilst fermentation is carried out over a period of 0.5-2.5 hours using the exogenous enzyme protosubtilin G3x.
Reference is also made to FR 2168259 which describes an enzymatic hydrolysis of fish proteins that is carried out by crushing fresh fish into a fine paste without adding water. Exogenous enzymes are added and the paste is hydrolysed for about 15 hours depending upon desired solubility. The product is stabilised for 5-20 minutes at +90°-+100° C., and is filtered, pasteurised and centrifuged. The process yields products of a high nutritional value.
As shown in the above, different techniques are known for releasing proteins, peptides and amino acids from fish which are suitable for food production. Moreover, it is also known to prepare oil/fat from raw materials from both plant and animal sources.